The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
Autonomous driving systems and freeway limited-ability autonomous driving (FLAAD) systems utilize inputs regarding the road, environment, and other driving conditions to automatically control throttle, braking and steering mechanisms. Accurate estimation and identification of a clear path over which to operate a motor vehicle is desirable in replacing the human mind as a control mechanism for vehicle operation.
In any autonomous driving system, it is desirable that critical electrical loads for providing operation of the vehicle when autonomous driving is enabled are supplied uninterrupted power for a period of time, e.g., 5 seconds, during faults in any one of the electrical power sources or power distribution paths so that appropriate controllers associated with the critical electrical loads continue to function during the period of time.
The critical electrical loads can include fail operation system (FOS) loads powering controllers for operating various actuators and systems required for autonomous driving, e.g., when a FLAAD mode is enabled. It is required that the FOS loads be fail operational and receive a redundant power supply even during electrical faults in the electrical system for at least 5 seconds. When FLAAD mode is enabled, a continuous fault diagnosis is monitored to detect the existence of any faults in the electrical system. When a fault is detected during autonomous driving, i.e., when the FLAAD mode is enabled, the vehicle is configured to temporarily switch to lane centering and requires an immediate driver take-over. Accordingly, the vehicle desirably maintains lateral/longitudinal for at least a predetermined period of time, e.g., 5 seconds, during the driver take-over.
It is known, for example, to provide back-up power using additional batteries or ultra-capacitors for each FOS load when a loss of power is detected. Additional batteries or ultra-capacitors add mass and increased package size for each FOS load; increase cost if sized to support each FOS load individually; and do not support the entire electrical system or controllers of the vehicle, but only supports those FOS loads to which the additional batteries or ultra-capacitors are assigned.